</screen>
<para>
-which should produce the files <filename>seteuid.o</filename> and
+which should produce the files <filename>seteuid.o</filename> and
<filename>setegid.o</filename>.
</para>
LIBSM = setegid.o seteuid.o -ln
</programlisting></para>
-<para>
+<para>
You should then remove the line:
</para>
127.0.0.1 loopback "hostname"."domainname"
</programlisting>
</para>
-
+
<para>
<indexterm><primary>loopback interface</primary></indexterm>
This causes Samba to loop back onto the loopback interface.
<title>AIX: Sequential Read Ahead</title>
<!-- From an email by William Jojo <jojowil@hvcc.edu> -->
<para>
-Disabling sequential read ahead using <userinput>vmtune -r 0</userinput> improves
-Samba performance significantly.
+Disabling sequential read ahead can improve Samba performance significantly
+when there is a relatively high level of multiprogramming (many smbd processes
+or mixed with another workload), not an abundance of physical memory or slower
+disk technology. These can cause AIX to have a higher WAIT values. Disabling
+sequential read-ahead can also have an adverse affect on other workloads in the
+system so you will need to evaluate other applications for impact.
+</para>
+
+<para>
+It is recommended to use the defaults provided by IBM, but if you experience a
+high amount of wait time, try disabling read-ahead with the following commands:
+</para>
+
+<para>
+For AIX 5.1 and earlier: <userinput>vmtune -r 0</userinput>
+</para>
+
+<para>
+For AIX 5.2 and later jfs filesystems: <userinput>ioo -o minpgahead=0</userinput>
+</para>
+
+<para>
+For AIX 5.2 and later jfs2 filesystems: <userinput>ioo -o j2_minPageReadAhead=0</userinput>
+</para>
+
+<para>
+If you have a mix of jfs and jfs2 filesystems on the same host, simply use both
+ioo commands.
</para>
</sect1>